I had a quick look at the Developer Bundle, and it uses an "engine.cfg", so it should be using something older than godot 3.0 (there that file would be named "project.godot") so probably some 2.1 version was used.
I don't have my Pandora with me right now so I can't test it, but looking at the screenshots I'd say it might even work without any or just some minor adjustments (maybe some in order to make it playable on the 800x480 screen and some in case the sprite textures aren't power of 2 and have mipmaps enabled).

Edit:
Running it on my Laptop it seems to be working fine with many different window sizes, so 800x480 shouldn't be a problem but mipmapping seems to be enabled by default, so some GLES driver versions of the Pandora might show some Sprites in black if there are any non power of two texture sizes.

Forever Homebrew

"OpenSSN is a submarine simulator (sometimes referred to as a subsim) for modern classes of submarine. The player is able to pilot their submarine, detect vessels and engage enemy ships. The game focuses on the tactical aspect of commanding a submarine, leaving many of the minor details up to the AI crew."

EDIT 3: I recompiled the game this morning while in the train, with all the optimizations frrom Code::Blocks (-O3 -ffast-math etc...). Not sure this is a great idea, considering this is a submarine simulation, with lots of advanced math involved (I could be wrong though...). The PND is almost ready, you can expect a release soon !

EDIT 4: PND is ready, but the game has many issues (it segfaults, for one thing. Even when recompiled with -O2 only), so I'm quite reluctant to release it on the Repo as is. I'll recompile it with debug flags, see if I can understand what's going wrong...

EDIT 5: of course, the game no longer segfaults when compiled with the debugging flags... Typical

Forever Homebrew

Rexuiz is a fast-pased 3D first person shooter game. Rexuiz is a revival of the game “Nexuiz Classic” (formerly known as “Nexuiz”) and thus very similar to that game. Rexuiz is compatible with Nexuiz Classic servers. The goal of the project is to create a high quality first person shooter that can be played freely across all platforms in one package, including GNU/Linux. The game is entirely free software and is able to run in low-end hardware.

I will have the same performances (so a couple of fps, at best, when outside), the "rain" fix are certainly good, but it is slow without rain anyway on the Pandora. OpenMW is too much for both CPU and GPU. I know gl4es is used on the Android port, and fps are pretty good there, but on much more powerfull phone then what the Pandora is...
Maybe I'll package it one day, and put it in the beta thread..